1. The Field of the Invention
This invention relates to pan and tilt heads for supporting a payload such as a TV, video or cine camera on a tripod, pedestal or other form of mounting.
2. The Relevant Technology
Our UK Patent Publication No. 2189042 discloses a tiltable mounting for a TV or video camera comprising a base, a tiltable support member pivoted thereto and reactionary moment producing means located between and operated from said base and tiltable support member to produce a reaction equal to the out of balance moment generated by the weight of an article mounted on said tiltable support member as said centre of gravity moves about the vertical. The means for producing the reactionary moment comprises a horizontally extending spring guide mounted on the base carrying a compression spring acting between a slide and an end stop. The slide is excentrically coupled to the support member with respect to the tilt axis so that tilting of support member with respect to the tilt axis so that tilting of the support causes the slide to compress the spring and produce a force to counterbalance the out of balance moment produced as the centre of gravity of an article mounted on the tiltable support member rotates about the vertical. The spring guide has a rotary adjusting device connected to the guide by a lead screw to preload the spring in relation to the weight and position of the centre of gravity of the article on the support which is located on a vertical member of the space on the rearward side of the head. Since very high loads are required in the spring to provide the requisite counterbalancing force, the effort required to rotate the adjustment device is considerable. Moreover the tiltable support covers the adjustment device when the support is tilted rearwardly making it impossible to effect an adjustment when the supported is in that position.